By Lewis Jackson

SYDNEY Australia will on Thursday introduce two previously announced tax bills that will raise petroleum tax revenue and legislate the government's response to a national scandal over confidential tax plans leaked by a PwC Australia partner.

Legislation to reform the Petroleum Resource Rent Tax (PRRT), first flagged in the May budget, will reduce the proportion of income which can be offset by deductions and is expected to raise A$2.4 billion ($1.56 billion) out to June 2027.

The change is one of 11 recommendations from a Treasury review, eight of which the government adopted in August. Consultation on further changes will begin later this year.

"The PRRT changes will ensure the offshore LNG industry pays more tax, sooner," Treasurer Jim Chalmers said in a statement late on Wednesday.

The centre-left Labor government will also on Thursday introduce legislation prepared in response to revelations a former PwC Australia partner leaked confidential government tax plans then used it to drum up work with multinational companies.

The previously announced reforms will raise the maximum penalty for promoting tax exploitation schemes 100-fold to A$780 million and make prosecution easier by expanding how the rules, which have only been used six times, are applied.

More changes could follow. Chalmers in August announced a two-year Treasury review into the rules governing large consulting and auditing firms.

($1 = 1.5389 Australian dollars)

(Reporting by Lewis Jackson; editing by Miral Fahmy)